fuller



(No Model.)

H. P. FULLER.

MANHOLE COVER SEATING. No. 575,475. Patented Jam. 1-9, 1897.

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HENRY F. FULLER, OF CHICAGO, ILLINOIS, ASSIGN OR TO TIIE IVALMSLEY,FULLER dr COMPANY, OF SAME PLACE.

IVIANHOLE-COVER SEATING.

SPECIFICATION forming part of' `Letters Patent No. 575,475, datedJanuary 19, 1897. Application tiled November 2, 1896. Serial No.610,853. (No model.)

To au whom t may concern.-

Beit known that I, HENRY F. FULLER, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois,

have invented a new and useful Improvement in Manhole-Cover Seating, ofwhich the following is a specification.

My invention relates to an improvement in the construction of the packedjunction be- 1o tween the cover of a manhole and the seat about thelatter for the cover.

The object of my improvement is to secure a perfectly air and gas tightclosure of a manhole by its cover without employing elaborate or undulycumbersome mechanism for the purpose. To this end I provide about themanhole a transversely-concave annular seat, the concavity beingdescribed on a circle of 4one radius to receive the packing, and Iform2o the flange about the cover transversely conveX, with the conveXitydescribed on a circle of greater radius. Thus with the packingrin g inplace whenthe cover is fastened down its iiange bears mainly against theopposite z 5 edges of the packing-ring, thereby compacting the packingand accordingly tightening the joint, and should there be any moisturein the cup-shaped seat the tendency will be to confine it and thuscompact the packing 3o the more, besides securing the sealing effect ofthe water.

My invention is illustrated in the accompanying drawings, in whicl1-Figure l shows a broken section of a gas- 3 5 generator equipped withilly-improvement, and Fig. 2 is a section taken at the line 2 on Fig. 1,viewed in the direction ofl the arrow and enlarged.

A is a manhole, shown to be provided in 4o the top of the inner tank Bof a gas-generator, though it may be equipped with my improvement in anyother situation in which it may be provided. 4

C is the bushing, shown to be riveted in place and provided in itshorizontal portion with the transversely-concave annular seat i' for thegasket D, which may be formed of rubber, though a liquid packing may beused.

E is the manhole-cover, of any suitable general form, provided with theperpendicular 5o annular iiange p, to fit inside the bushing and havingthe outward-extending flange o transversely convex on its under side,the convexity being formed on a circle of greater radius than that onwhich the concave seat?1 55 is formed.

Then the cover E is tightened and held down in place, as by theclamping-bar arrangement F illustrated, which is a wellknown device forthe purpose and therefore 6o requires no detailed description herein,the convex flange o bears against the opposite edges of the gasket,thereby compacting it toward its center and accordingly tightening thejoint, and any water that may be contained in the annular concavity raffording the gasket-seat will be crowded against the central portion ofthe underside of the gasket and tend to increase the hermetical qualityof the junction by affording a water-seal.. 7o

What I claim as new, and desire to secure by Letters Patent, is-

1. In combination with a manhole, an an nular transversely-concavepacking-seat, a cover having an annular iiange the under side of whichis of slight transverse conveXity as compared with the degree of'concavity of the seat, forming with said seat a concavoconvex recess,and an elastic packing within said recess adapted by pressure to conform8o thereto and to be centrally' compressed in the manner and for thepurpose.substantially as described.

2. In combination with amanhole, an annular transversely-concavepacking-seat hav 8 5 ing its concavity formed on a circle of one radius,an elastic packing in said seat, and a cover having a flangetransversely convex on its under side on a circle of greater radius,whereby its pressure upon the elastic pack- 9o ing will cause the saineto be compacted toward its center, substantially as described.

p HENRY F. FULLER.

Inpresence of J. H. LEE, R. T. SPENCER.

